Gates Creek Salmonid Population Assessment, Spring and Summer 2016 Implementation Year 5 (2016): FWCP Project No: COA-F17-1360 Reference: GATESCHAN 0009 Stephanie Lingard, Daniel Ramos- Espinoza, Nicholas Burnett, Douglas Braun and Caroline Melville Prepared for: The Fish and Wildlife Compensation Program Lillooet Tribal Council Fisheries and Oceans Canada Prepared by: InStream Fisheries Research Inc. 1211A Enterprise Way Squamish BC, V8B 0E8 Report prepared with financial support of the Fish and Wildlife Compensation Program on behalf of its program partners BC Hydro, the Province of BC, First Nation and Public Stake Holders and Fisheries and Oceans Canada. Executive Summary This report summarizes the monitoring activities of the Gates Creek Salmonid Habitat and Population Assessment. The project was funded by the Fish and Wildlife Compensation Program. The Gates Creek Salmonid Habitat and Population Assessment primarily addresses the "research and information acquisition" action in the Bridge Seton Salmonid Action Plan by providing baseline population estimates for rearing salmonids in the Gates Creek watershed. This report is broken into two chapters to accommodate the difference in methodologies used between the two field components of the project. The “Gates Creek Juvenile Sockeye Salmon Migration and Survival” is the first chapter and discusses the final year of data collection for juvenile Sockeye Salmon that commenced in the spring of 2012. The chapter summarizes the abundance and survival estimates for Sockeye Salmon fry leaving Gates Creek and the Gates Creek spawning channel over the past five years with emphasis on the data collected in the spring of 2016. The second chapter, the “Gates Creek Juvenile Salmonid Assessment” presents the results of the first year of a proposed four-year open site electrofishing mark-recapture survey for juvenile Coho Salmon, Bull Trout and Rainbow Trout. Fish density for age 0+ Rainbow Trout and catch statistics for Coho Salmon and Bull Trout juveniles are provided in this chapter. Table of Contents Project Background ..................................................................................................................................... 11 Chapter 1: Gates Creek Juvenile Sockeye Salmon Migration and Survival ................................................. 12 1.0 INTRODUCTION ................................................................................................................................. 1 1.1 Study Objectives ........................................................................................................................... 1 1.2 Study Area and Trapping Locations .............................................................................................. 1 2.0 METHODS .......................................................................................................................................... 1 2.1 Fish Trap Operations ..................................................................................................................... 2 2.1.1 Gates Creek Traps - Inclined Plane Trap (IPT) ....................................................................... 2 2.1.2 Channel Trap ......................................................................................................................... 2 2.2 Sockeye Fry Marking and Recapture............................................................................................. 2 2.3 Length and Weight Sampling of Sockeye Fry ................................................................................ 3 2.4 Environmental Monitoring ............................................................................................................ 3 2.4.1 Water Level ........................................................................................................................... 3 2.4.2 Water Temperature .............................................................................................................. 3 2.5 Population Estimate Methods ...................................................................................................... 4 2.5.1 Total Sockeye Salmon Fry Abundance .................................................................................. 4 2.5.2 Gates Creek Spawning Channel Sockeye Salmon Fry Abundance ........................................ 5 2.5.3 Gates Creek Sockeye Salmon Fry Abundance ....................................................................... 5 2.5.4 Egg-to-fry Survival and Fry per Effective Female .................................................................. 5 3.0 RESULTS............................................................................................................................................. 5 3.1 Fish Trap Operations ..................................................................................................................... 5 3.1.1 IPT.......................................................................................................................................... 5 3.1.2 Channel Trap ......................................................................................................................... 6 3.2 Bio-Sampling of Sockeye Salmon Fry ............................................................................................ 6 3.3 Environmental Monitoring ............................................................................................................ 6 3.3.1 Water Level ........................................................................................................................... 7 3.3.2 Water Temperature .............................................................................................................. 7 3.4 Sockeye Salmon Population Estimates ......................................................................................... 7 3.4.1 Total Abundance of Sockeye Salmon Fry .............................................................................. 7 3.4.2 Gates Creek Spawning Channel Sockeye Salmon Fry Abundance ........................................ 8 3.4.3 Gates Creek Sockeye Salmon Fry Abundance ....................................................................... 8 3.4.4 Egg-to-fry Survival and Fry per Effective Female .................................................................. 8 4.0 DISCUSSION ....................................................................................................................................... 9 4.1 Trap Operations ............................................................................................................................ 9 Channel Trap ......................................................................................................................................... 9 4.2 Bio sampling-Sockeye Fry ............................................................................................................. 9 4.3 Sockeye Salmon Fry Migration .................................................................................................... 10 4.3.1 Sockeye Salmon Fry Abundance ......................................................................................... 10 4.3.2 Egg-to-Fry Survival and Fry per Effective Female ............................................................... 11 4.3.3 Sockeye Fry Run-Timing ...................................................................................................... 12 5.0 SUMMARY and RECOMMENDATIONS ............................................................................................ 12 6.0 TABLES ............................................................................................................................................. 14 7.0 FIGURES ........................................................................................................................................... 21 8.0 REFERENCES .................................................................................................................................... 31 Chapter 2 Gates Creek Juvenile Standing Crop Assessment of Coho Salmon, Bull Trout and Rainbow Trout Juveniles ............................................................................................................................................ 34 9.0 INTRODUCTION ............................................................................................................................... 39 9.1 Study Objectives ......................................................................................................................... 39 9.2 Study Area ................................................................................................................................... 39 10.0 METHODS ........................................................................................................................................ 39 10.1 Site Selection ............................................................................................................................... 40 10.2 Field Survey ................................................................................................................................. 40 10.3 Age Class Determination ............................................................................................................. 41 10.4 Population Density Estimates ..................................................................................................... 41 11.0 RESULTS..........................................................................................................................................